Phonograph system



. Nov. 28, 1939- M. L. BRADFIELD 2.181505 yuouoemru SYSTEM Filed March 10, 1938 INVENTOR TORNEY Patented Nov. 28, 1939 PATENT OFFICE 2,181,505 rnonocnsrn srs'rnm m L. Bradfleld, Tex-re Hantc, ma, assignor to Thomas A. .Edison, Incorporated,

West

, Orange, N. 1., a corporation of New Jersey Application March 10, 1938, Serial No. 195.026 10 Claims. (01. 179-6) This invention relates phonograph systems and more particularly to means for controlling.

and adapting phonograph-recording systems to perform a'plurality of functions' It is primarily concerned with phonograph-recording systems which are arranged so that they may be operated to transmit sounds and conversations as for inter-oilice communicating purposes.

A phonograph system for recording sounds and conversations may employ an electro-acoustical source of oscillations such, for example, as a microphone or telephone, an electrical amplifier for amplifying such oscillationsanda suitable phonograph for receiving and recording these oscillations. Such recording systems comprise the basic elements of sound transmitting systems of the type which may besuitably employed for inter-oflice communicating purposes. Thus by proper arrangement and control of 'these basic elements there may be conveniently provided a 1 simplified form of a combined sound-recording and sound-transmitting" system. Since soundrecording systems are commonly employed for the recordation of dictation and business conversations by those who often have need for interofilce communicating equipment, it ishighly desirable for reasons of economy and facilityof operation, to provide such means as will permit a phonograph-recording system to fulfill also the function of a sound-transmitting system. Such a combined system of sound recording and sound transmitting may be arranged for the use of any plurality of operators of which any number of the operators may be providedwith facilities for sound recording and/or one or two way sound transmission. This system may moreover be controlled and/or operated by conveniently arranged control means facilitating .the use of the system.

'40 It is an object of my invention to provide, in

a phonograph-recording system, means whereby the recording system may fulfill a plurality of functions.

It,is another object to provide an economical arrangement of a combined phonograph-recording and sound-transmitting system which is conveniently arranged for easy controland operation. o v

It is another object to provide, in a phono-' graph-recording. system, a plurality of electro acoustical devices and a plurality of control devices whereby the systemmay be operated for sound recording purposes from one or'more locations and may also be adapted for sound-transmitting purposes such as for inter-omce communication.

It is .another object to provide in a system of sound recording and sound transmitting, means for controlling and adapting the system for any 6 one of its several specific functions by a single manipulation of a switch device. 1

It is another object to providein a system of sound recording and sound transmitting, a plurality.. of control stations respectively having l0 sound-transmitting and sound-receiving devices and control means operable to provide one-way sound transmitting facilities therefrom, of which at least one of the control means is operable to adapt the system for sound recording. 15

Other and allied objects will more fully appear from the following description and the appended claims. e In the description of my invention, reference is had to the accompanying drawing which is a go. schematic diagram of, a phonograph-recording system in which my invention is incorporated.

' The portion of the accompanying drawing which comprises the phonograph A may first be described. This phonograph may be of any suit- 25 able variety for receiving and recording soundrepresenting electricoscillations. In a form such as is common in the recordation of dictation and I other conversations the phonograph A may comprise a mandrel I adapted for removably carry- 30 ing a cylindrical record 2; a carriage Shearing a sound-translating device 4 adapted for recording .on the record 2, the carriage 2 being adapted to be driven-longitudinally of the record 2 as along a guide rod 5 by means of a feed screw .6; a 5 motor I suitably arranged to provide rotational movement of the mandrel and longitudinal movement (in a right-hand direction) of the translating device; a train of gears 8 coupling the feed screw 6 with the mandrel I; and a clutch 9 inter- 40 posed between the mandrel l and the driving means therefor. v

The translating device lis adapted, when in an operative condition, to receive electric oscillations, as byway of the terminals Ill, and to 5 -from engagement with the record 2, thereby permitting the removal of the record 2 from the able electro-acoustical means for receiving sound waves and translating these waves into corresponding electric oscillations. Such electroacoustical means may be of any suitable variety, such as a microphone or telephone. These means may be located, if desired, in the room in which the phonograph A is located. It will be understood, however, that the location of the phonograph with respect to that of the electro-acoustical means is relatively unimportant as long as they are separated sufiiciently to avoid feedback; The phonograph A may, for example,'be very desirably located in a room l2, or other suitable location, and the electro-acoustical device or microphone l3 in another room such as I4.

The output of the microphonet '|3 is usually of relatively low level and therefore suitable means for amplifying the microphone output is provided, such as the electrical amplifier. l5 which feeds into the translating device 4, as by way of the circuit IS. The output of the microphone i3 is also very desirably controlled by a suitable attenuating means or volume control I! which is serially connected in a circuit l8 leading from the microphone I3. During periods of temporary non-use of the machine it is desirable to have the microphone 3 disconnected from the amplifier l5, as such connection may tend to cause extraneous and objectionable sounds to be radiated from. the translating device 4 during such periods. These, radiated sounds may moreover tend to be fed back into the microphone l3 and cause objectionable 'howlingsound effects. In .order that the microphone l3 may be disconnected from the input of the amplifier l5,

the circuit I8 is connected with the pole mem-' bers l9 and 20 of a multiple switch 2| having upward and downward closed positions and a central open, or neutral position. When the switch 2| is in its downwardposition these respective pole members are closed with the contact members 22 and 23 to make connection with the input of the amplifier l5 by way of the circuit 24.

During periods of non-use of the phonographrecording system, it is desirable that the phonograph be inoperative. The phonograph may be rendered inoperative and operative simultaneously with the disconnection and reconnection of the microphone III with the amplifier l5. To efiect such control of the phonograph there is provided suitable switch means comprising the pole member 25 and the contact member 26 of the multiple switch 2|. These switch means are arranged to close a. circuit 2'| to connect the motor 1 with a suitable source of power, as the switch 2| is operated from its neutral position to its downward closed position. By this means record rotation is started and stopped to put the phonograph into and out of operation as the microphone I3 is respectively connected with and disconnetced from the amplifier IS. The manher by which the phonograph A is to be put into and out of operation is however an arbitrary one since such control of the phonograph may, for

example. be also effected by any suitable means for operating the clutch 9 or the control lever II.

It may be desirable to provide a plurality of means whereby the phonograph A is operable by any one of a "group of operators. Such additional means may, for example, be placed in a location or room 28; in the drawing they have been designated with numbers similar to those for the corresponding, components as provided in room I4 but having prime marks-such as a micro phone l3, a volume 'control l1, and a multiple switch 2|. As in the case of the switch 2|, the switch 2| is provided with the pole members l9 and 20 and the contact members 22' and 23' for closing and opening a circuit adapted to connect the microphone I3 with the input of the amplifier l5, and with the pole member 25 and 2| and 2|, each of which are connected across the motor 1, as by the respective circuits 30 and 30. Thus each of these lamps are lighted whenever the phonograph A is put in an operative condition. I

A phonograph recording system, as heretofore described, comprises the basic elements of a sound transmitting system. By proper arrangement and control of these basic elements, as according to my invention, they may be utilized in a combined phonograph-recording system and sound-transmitting system such as is commonly used for inter-office communicating purposes. These normally separately attained functions of sound recording and sound transmitting may therefore be effected with one integrated installation. This integrated installation may then be of simple and economical arrangement, and easily adapted to efiect any one of its specific functions.

y In order that the operator of microphone l3, located in rgom It, may communicate with an operator in-some other location, which may be contact member 34 which are interposed in the circuit 32 and which are closed with each other as the switch 2| is operated to its upward position. In order that the operator in room 23 may also communicate with the operator in room. ll, there is also provided a sound reproducer 3|, such as 3|, which is located in room I. The sound reproducer 3| is also adapted to be connected across the output of the amplifier l5, as by way of the circuit 32', at the will of the operator in room 28 by the manipulation of the multiple switch 2| to its upward position. As i the case of the switch 2|, thisconnection is efi cted by-the pole member 33' and contact member 34' which are interposed in the circuit 32' and which are closed with each other as the switch 2| is operated to its upward position.

Whenever the sound transmitting system is are placed in the same vicinity, or room, a microphone and sound reproducer respectively connected across the input and output of the amplifier l5. There will then tend to be acoustic feedback between the microphone and sound reproducer because of their juxtaposition. Moreover, the amplifying requirements are usually considerably greater for a sound-recording system than for a sound-transmitting system, and

therefore, in a. combined sound-recording. and

sound-transmittingsystem this feedback tendency is greatly augmented. It is however a feature of my invention to provide simple means by which the effective gain of the system is adjusted to a proper value whenever it is to be used for sound-transmitting purposes, thereby mitigating the tendency for acoustical feedbaclo. The means for efiectingthis adjustment comprises an attenuator 35 which is automatically interposed into the circuit connecting the microphone |3 with theinput of the amplifier l5 as the switch 2| is thrown into its upward position. In order that the attenuator 35 may be so interposed, it is serially provided in a circuit 36 which is connected from the contact members 22 and 23 to a set of contact members 31 and 38 respectively arranged for closing with the pole members l9 and as the switch 2| isthrown to its upward position. Thus the gain of the system is properly adjusted and the sound reproducer 3| is simultaneously connected across the amplifier output so that'the system is properly conditioned for one way sound transmission as the switch 2| is thrown to its upward position. It will be understood that'according to my invention the means whereby the gain of the system isproperly adjusted for soundrecording and sound transmitting is an arbitrary one, as such adjustment of the gain may be effected in. many suitable ways.

The switch 2| may be in all respects similar to the switch 2|, it being provided with the contact members 31' and 38' corresponding to the contactmembers 31 and 38 of the switch 2|. Between the set of contact members 31' and 38' and the set 22' and 23"there is interposed a circuit 36' which is serially provided with an attenuator such as the attenuator 35. As the switch 2| is thrown to its upward position the contact members 31' and 38' are closed with the respective pole members l9 and 20' to connect the microphone IS' with the input of the amplifier l5, and the pole member 33' is closed with the contact member 34 to connect the sound reproducer 3| across the output of the amplifier 15, thereby conditioning the system for one way sound trans-- mission as from the microphone l3.

As the switches 2| and 2| are in their respective neutral or upward positions the power circuit 21 is open and the phonograph A is rendered inoperative. The phonograph A is however put in .operative condition whenever either of the switches 2| and 2| is .operated to its downward position to condition the system for sound recording.

During the non-use of the system each operator will normally have his respective control switch in its neutral position. If either operator should desire to record, he will place his control switch in its recording position, thereby operating the signaling system to inform the other operator that the phonograph A is in an operative condition. If however either operatorshould desire to I communicate with the other he will operate his tenuating means connected 3 control switch to its upward position, and the other operator, in order to provide two-way communication, will also operate his control switch to its upward position.

Although I have illustrated my invention-with a specific embodiment it will be understood that a many changes and modifications may be made therein without departing from the scope of my invention. There may, for example, be provided any plurality of electro-ac'oustical devices and of control means for connecting these devices into the system and for controlling the phonograph,

as desired. These electro-acoustical devices may be connected into the system singly or in any suitable combination so that any operator may communicate with any other or any group of operators. Such and other modifications will not necessarily depart from the scope of my invention which I undertake to express according to the following claims.

I claim: I

l. The combination in a system comprising a phonograph having means for rotating a record and a translating device cooperating with said record of an electrical amplifier connected to said translating device; a microphone for the input of said amplifier; a sound reproducer for the output of said amplifier; andaunitary switch device having a position for connecting said microphone and said sound reproducer with said amplifier, and another position for connecting said microphone with said amplifier and for rendering said record-rotating means operative.

2. In a system of the character described, the combination of a phonograph having means for moving a record and a translating device adapted to cooperate with said record; an electrical amplifying arrangement adapted'for connection in the system so as to function either with 9. normal gain or a modified gain; an electro-acoustical source of oscillation a sound reproducer associated with the output of said amplifying arrangement; and means operable to connect said source of oscillation with said reproducer through said amplifying arrangement with the latter connected in the system so as to function with such modified gain, and also operable to render said phonograph operative and simultaneouslyto connect said electro-acoustical source of oscillation with said translating device by way of said amplifying arrangement with the latter connected in the system so as to function with a normal gain.

3. In a system of the character described, thev combination of a phonograph having means for crating with said record; an electro-acoustical source of oscillations; a sound reproducer; and adjustable means including a controllable amplifying arrangement, der said record-moving means operative and simultaneously to amplify said oscillations with normal gain and feed the same into said' translating device, and to amplify said oscillations with a modified gain and feed the same into said reproducer.

4. A system interoffice communicating purposes comprising means for rotating a record; a translating device cooperating with said record; an electrical ,amplifier connected to said translating device; at-

microphone; a sound reproducer for the output of said amplifier; and switch means having a position for simultaneously rendering said phonograph operative and connectins said microphone selectively operable'to renfor phonograph recording and to said amplifier; a

nected to said recording means; attenuating means connected to said amplifying means; 'a plurality of control stations each comprising a microphone; a sound reproducer and a switch means, each of said switch means having a position for simultaneously rendering said recordrotating means operative and connecting the microphone of the control station with the input of said amplifier, and having another position for simultaneously connecting the microphone of its control station with the input of said attenuating means and a sound reproducer of one 'of the other control stations with the output of said amplifier.

6. In a system of the character described, the combination of a phonograph having recordmoving means and a record-cooperating sound translating device; means for amplifying oscillations fed to said translating device, having an input and an output; and a plurality of control stations each comprising a microphone, a sound reproducer and a switch means, each of said switch means being selectively operable to connect the microphone of its control station with the input of said amplifying means and to coordinately render said record-moving means onerative, or to render said record-moving means inoperative and to coordinately connect the microphone of its control station and a sound reproducer of one of the other of said control stations with the input and output of said amplifying means respectively.

7. The combination as claimed in claim 6, wherein each of said switch means is further selectively operable to render said record-moving means inoperative and to coordinately disconnect both the microphone of its. control station and the sound reproducer of the said other control station from said amplifying means.

8. A system for recording and transmitting sounds and conversations comprising phonograph recording means; and a plurality of control stations each comprising a microphone, a sound reproducer and a unitary switch device, each of said unitary switch devices including means operable at will to connect the microphone of its-control station with a sound reproducer of one of the other controLstations to form a one-way sound communicating channel between said control stations, and at least one of said switch devices including means for rendering said phonograph recording means operative, at will, to permit the recordation of sound from the microphone associated with said one switch device.

9. In a system of the character described, the combination. of a phonograph having recordmoving means and a record-cooperating sound translating device; an amplifying arrangement connectable so as to function either with a normal gain or a modified gain; and a plurality of control stations each comprising a microphone, a sound reproducer and a switch means, each of said switch means having aposition for connecting the microphone of its control station with the sound reproducer of at least one-of the other control stations by way of said amplifying arrangement with the-latter connected so as to function with a modified gain, and having another position for'rendering said record-moving means operative and concurrently connecting the microphone of its control station with said translating device by way of said amplifying arrangement with the latter connected so as to function with a normal gain.

10. In a system of the character described, the combination of a phonograph having recordmovin'g means and a record-cooperating sound translating device; means for amplifying oscillations fed to said translating device, having an input and an output; and a plurality of control stations each comprising a microphone, a sound reproducer and a switch means, one of said switch means having a position for connecting the mlcrophone of its control station with the input of said amplifying means and coordinately rendering said record-moving means operative and another position for rendering said record-moving means inoperative and coordinately connect ing the microphone of its control station and the sound reproducer of at least one of the other 1 of said control stations with the input and output of said amplifying means respectively, and

-the other of said switch means being respectively operable to concurrently connect, at will,

the microphone of their respective control sta- 

